1. Field of the Invention
The present invention generally relates to systems and methods for controlling area lighting. More particularly, the present invention relates to lighting systems and methods for controlling indoor lighting by providing flexible and programmable control based on occupancy and daylight contribution.
2. Discussion of the Background
Indoor facilities such as classrooms require robust, capable and flexible lighting and control solutions that serve the user and save energy. Static lighting systems designed to IES specifications service only a small portion of the actual lighting requirements that exist in today's classroom environment.
Complicating the design of these solutions are energy codes, which are becoming more and more restrictive on schools: ASHRAE Standard 90.1-1999/2001 prescribes a maximum power density of 1.6 W/sq·ft for classrooms. ASHRAE 90.1-2004/2007 goes further with a prescribed 1.4 W/sq·ft and California's Title 24-2005 takes it even further with a requirement for a maximum density of 1.2 W/sq·ft.
To service the needs of the educator and to support the educational environment, classroom lighting and control solutions must be flexible and capable of providing multiple lighting scenarios “visual environments” that support or enhance the varied educational tools which may be utilized such as whiteboard, video and multimedia presentations. The modern classroom requires a range of lighting scenarios, from full lighting for traditional teaching to various levels of dimming and light distribution for audiovisual (A/V) presentations and other activities. Most existing systems don't have the flexibility to provide high-quality lighting in this varying environment. Typical classroom lighting solutions do not meet the functional needs of teachers or students. Classroom lighting and control solutions must be energy efficient. Occupancy Sensing, Daylight Harvesting and Demand Response energy saving strategies can all be deployed in these spaces to significantly reduce energy costs and meet codes and regulations. Most importantly, a successful classroom lighting and control solution must be cost effective, simple to install and commission, easy to understand and simple to use.